Universal electrode clamps



May 2, 1967 R. BosoLD UNIVERSAL ELECTRODE CLAMPS 2 Sheets-Sheet l Filed Jan. '7, 1964 INVENTOR LEONARD R. BOSOLD BY l /f /Mw ATTORNEY Maly 2, H967 l.. R* BosoLD UNIVERSAL ELECTRODE CLAMPS 2 Sheets-Sheet 2 Filed Jan. 7, 1964 IN VEN'I'OR.

LEONARD R. BSOLD ATTORNEY United States Patent 3,317,647 UNIVERSAL ELECTRODE CLAMPS Leonard R. Bosold, Massillon, Ohio, assignor to Republic Steel Corporation, Cleveland, Ohio, a corporation of New Jersey Filed Jan. 7, 1964, Ser. No. 336,247 Claims. (Cl. 13-16) This invention relates generally to consumable electrode melting, and more specifically to new and improved electrode clamping structure.

The present invention is particularly concerned with the provision of novel clamping devices for consumable metallic electrodes of the type currently used in the manufacture of high purity alloys. Electrodes of this type are usually sintered or cast of a desired alloy and are re-melted in use by being charged into a suitable furnace, such as a vacuum-arc consumable electrode melting furnace. The furnace into which the electrodes arecharged generally include a vertically acting power ram to which one end of the electrode is connected, the ram being operated to lower the consumable electrode into the vacuum chamber during the melting operation.

Various clamping arrangements have been devised in the past for connecting electrodes of the type described to the furnace rams; however, because of the considerations involved, none of the known devices have been completely satisfactory. For example, it is highly desirable to have a clamping device which permits quick changing of the electrodes being charged into the melting furnace. At the same time, the clamping structure should be relatively inexpensive so as to minimize maintenance costs. Other considerations are that the clamping structure provides for good current flow into the electrode and that it be adaptable to furnace rams of various sizes. The new and improved electrode clamping devices of this invention meet all of the considerations discussed above. As distinguished from many of the prior art constructionsrwhich cannot be readily connected and disconnected from the electrodes, the clamping structure of the invention is` such that it is possible easily and quickly to connect the electrodes to the furnace rams. Another feature of the invention is that the new clamping devices provide for self-alignment of the electrodes in a vertical direction. These features of partial self-alignment and quick attachment make it possible to change electrode assemblies in a minimum amount of time.

As will be described in detail, the construction of the new electrodeelamping structure is relatively simple and is essentially comprised of a stub which is suitably connected to the electrode and a novel stub holder which is attachable to the furnace ram. The holder serves to seat the stub in a manner which provides for the vertical selfalignment feature previously mentioned and preferably includes structure for locking the stub in the holder. Because of its simplicity of construction, the clamping device is inexpensive and reduces maintenance costs. At the same time, the holder and stub cooperate to enhance current ow and are capable of supporting large weights. The holder itself is adapted to be attached to rams of different sizes so as to provide a versatile electrode clamp.l

Other features and advantages of the invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings.

In the drawings:

FIGURE 1 is a side elevational view of the preferred clamping device construction contemplated by the invention;

FIGURE 2 is a vertical cross-sectional view of the construction illustrated in FIG. 1;

FIGURE 3 is a side elevational view of bodiment of the invention; and v a modified em- FIGURE 4 is a vertical cross-sectional view of the construction illustrated in FIG. 3.

Referring now to the drawings, and to FIGS. 1 and 2, the new and improved electrode clamping device of the inventi-on is indicated by reference numeral 10. As generally described above, the clamping device 10 comprises an electrode stub 11 and a stub holder 12. The stub holder 12 includes a clamp body 13 in which the stub 11 is mounted during use.

In its preferred form, the electrode stub 11 is wedgelike and includes flat, parallel end surfaces 14 and side surfaces 15 which converge from a llat upper surface 16 to a neck 17 adjacent the opposite end of the stub. The opposite end of the stub 11 is chamfered at 18 and is provided with an extending threaded stud 19. In use the stub 11 is preferably connected to an end of the consumable electrode by an intermediate member in the form of a metal plate 20. As shown in FIGS. 1 and 2, the threaded stud 18 is engaged in a hole 21 formed in a metal plate 20 and a weld is provided between the stub 11 and the surface of the plate around the hole 21. The plate 20 is in turn welded to the end of the consumable electrode which may be of Ithe type described above and which is illustrated by broken lines at 22.

The clamp body 13 is cylindrical and is constructed so that it is readily connectible to furnace rams of different sizes. To this end, the upper end wall 30 of the clamp body is formed to engage a platen on the end of a furnace ram 32. The platen 31 and the clamp body are connected by screws 33 which are threaded into the upper end wall of the clamp body and are secured to the platen by nuts 34.

In accordance with this invention, the clamp body 13 has a stub-receiving vrecess 40. As shown, the recess 40 is generally cylindrical and is defined by end Walls 41, 42 and a side wall 43. A side wall opening 44 is formed in the clamp body through the end wall 41 of the cylindrical recess 40. The shape of the opening 44 generally corresponds to the wedge-like configuration of the electrode stub 11 which is inserted through the opening into the cylindrical recess between the end walls 41, 42 when assembling the device 1t). Another opening 45 is formed through the bottom end wall of the clamp body 13 into the side 43 of the recess 40. The stub 11 projects through the opening 45 when the stub is positioned in the recess as shown in FIGS. 1 and 2.

The stub holder 12 also induces a tapered seat in the recess 40 for seating the wedge-like electrode stub 11. In accordance with the invention, this tapered seat is formed by contact shims 50 which are mounted between the end walls 41, 42 of the recess 40 on opposite sides of the opening 45. Each of the shims 50 has an arcuate surface 51 conforming to the curvature of the cylindrical recess 40 and a flat face 52 which engages one of the converging side surfaces 15 of the electrode stub. In the embodiment of FIGS. l and 2, the shims 50 are mounted in the recess 40 by set screws 53 so that the ilat faces 52 of the shims form a continuation of the downwar-dly converging sides of the opening 44. The set screws 53 are threaded into the side wall of the cylindrical clamp body 13 and the finished ends of the set screws are engaged in holes formed in opposite ends of each of the shims 50.

The stub holder 12 further includes suitable locking structure for maintaining the wedge-like stub against the tapered seat formed by the shims 50. In the embodiment of FIGS. l and 2, the stub-locking structure comprises bolts 55. The bolts 55 are threaded into holes in the bottom of the clamp body 13 on opposite sides of the opening 45 and the heads of the bolts bear against the upper surface of the plate 20.

When connecting the electrode 22 to the furnace ram 32, the electrode with the attached plate 20 and the stub 11 are iirst inserted into the furnace and the clamp body 13 is secured to the platen 31. The clamp body 13 and the stub 11 are then moved together to insert the stub through the opening 44 into the recess 40. The ram 32 is subsequently raised so that the full electrode weight is imposed on the tapered seat formed by the shims 50. Because of the tapered seat formation in the recess 40, the electrode will be vertically self-aligning when the de- Vice is assembled in the manner described. After raising the ram to vertically align the electrode, the bolts 55 may be adjusted in the clamp body until the heads of the bolts are in engagement with the plate 20. The bolts 55 serve to maintain the electrode in its self-aligned position and also hold the stub 11 against the tapered seat so that the electrode assembly `can be lowered in the furnace for the melting operation.

It will be apparent from the foregoing description that the clamping structure 10 is the essence of simplicity and is of a construction such that consumable electrodes can be quickly changed and aligned in the furnace in a minimum amount of time. The essential operations involved in mounting the electrode assembly are merely that of positioning the stub in the clamp body and adjusting the readily accessible bolts 5S. Thus, the simplicity of design and the speed with which the electrodes can be changed achieve the objectives of a quick change, low cost clamping structure which greatly reduces maintenance expenses.

Reference is now made to FIGS. 3 and 4 which illustrate a modified embodiment 60 of the invention. -The clamping `device 60 is similar in construction to the previously described embodi-ment of FIGS. l and 2 and is generally composed of an electrode stub 61 and a stub holder 62. The clamp body of the stub holder 62 is designated by reference numeral 63.

In the illustrated modified embodiment of the invention, the stub 61 is shown as having a cylindrical end portion 64 which is formed with a chamfered end face 65. In use the end portion 64 may be welded directly to the end of the consumable electrode 22. The opposite end portion 66 of the stub 61 is Wedge-like and includes side surfaces 67 which converge from a flat upper surface 68 toward the end portion 64. An integral collar 69 is formed between the cylindrical portion 64 and the wedge-like portion 66.

As in the embodiment of FIGS. 1 and 2, the clamp body 63 includes a generally cylindrical recess 70 which is delined by end walls 71, 72 and by a side wall 73. A side wall opening 74 is formed in the clamp body through the recess end wall 71 and another opening 75 is formed through the bottom end wall of the clamp body into the side wall 73 of the recess 70. The upper end wall of the clamp body 63 may include a recess 76 which is adapted to seat the platen 31 on the end of the furnace ram 32. The platen 31 and the clamp body are connected by screws 77 and cooperating bolts 78.

The tapered seat for the Wedge-like portion 66 of the electrode stub is formed by shims 80 which are similar in construction to the shims 50` of FIGS. l and 2. In the modified construction of the invention, the shims 80 are mounted in the recess 70 by pins 81 which extend laterally through the clamp body 63 and through holes formed in the shims. The locking structure for locking the ywedge-like stub portion 66 against the tapered seat formed by the shims 80 is generally indicated by reference numeral 84. As shown, the locking structure 84 is cornprised of a lock member 85 which projects into the opening 74. The lock member 85 is in the form of a block which is detachably connected to the electrode stub 61 by a pin 86. The pin 86 is received in a hole formed in the stub portion 66 between the converging side surfaces 67. A screw 87 is threaded into the lock -member 85 and bears against the flat upper wall 88 of the opening 74.

The operation followed in connecting the elect-rode 22 to the ram 32 by means of the modified clamping de- 4 vice 60 is substantially the same as that described in connection with the preferred device 10. In summary, the electrode with the attached stub 61 are iirst inserted into the furnace and the clamp body 63 secured to the ram. The clamp body and stub are then moved together to insert the stub portion 66 through the opening 74 into the recess 70. When the ram 32 is subsequently raised, the electrode is vertically self-aligned and its full weight is imposed upon the tapered seat formed by the shi-ms 80. The lock member may be then connected to the stub 61 so as to project into the opening 74 and the screw 87 rotated until its head is in engagement with the clamp body surface 88. The screw 87 and the lock member cooperate to hold the stub against the tapered seat when the electrode assembly is lowered for the melting operation.

It will thus be seen that the modiiied clamping structure 60 also is of relatively simple construction and is such that the electrodes can be quickly changed and aligned in the melting furnace in a minimum amount of time. In addition to the advantages obtained from the quick change, low cost clamp construction, both embodiments of the invention provide for large positive contact between the electrode stub and the tapered seat of the stub holder. This large contact area assures that the electrode assembly Will remain fixed in its adjusted position and also enhances current flow into the stub during melting. The current iiow into the stub can be further promoted by forming the contact shims of the suitable currentconducting copper alloy.

Many modifications and variations of the invention will be apparent to those skilled in the art in view of the foregoing detailed disclosure. Therefore, it is to be understood that, within the scope of the appended claims, the invention can be practiced otherwise than as specifically shown and described.

What is claimed is:

1. An electrode clamping (a) an electrode stub,

(b) said stub having an end portion adapted to be connected to an electrode and surface portions converging toward said end portion, and

(c) stub holder means for permitting vertical self-alignment of said stub and a connected electrode and for locking said stub in aligned position, Y

(d) said holder means including a seat having surfaces engageable with said stub surface portions, said stub surface portions being movable on said seat to permit vertical self-alignment of said stub when the weight of said stub and a connected electrode is supported by said holder means, and releasable locking means for maintaining saidV stub against said seat with the electrode in vertically aligned position.

2. An electrode clamping device 4as claimed in claim 1 wherein said seat surfaces are flat and are disposed on two opposite sides of said stub when said stub is engaged by said holder means, and wherein said at seat surfaces converge toward said end portion of said stub.

3. An electrode clamping device comprising:

(a) an electrode stub adapted to be connected to an electrode,

(b) said stub including an end portion `and surface portions converging toward said end portion, and

(c) holder means for said stub,

(d) said holder means including a clamp body and a tapered seat formed in said body,

(e) said clamp body havinga side wall opening through which said stub can be inserted to engage said surface portions with said seat, and an end wall opening through which said stub projects when engaged by said seat,

(f) and said holder means further including locking means operatively engageable between said clamp body and .said stub to lock it against said seat.

l4. An electrode assembly comprising:

(a) an electrode,

device comprising:

(b) a stub connected to said electrode,

(c) said stub including an end portion adjacent said electrode and surface portions converging toward said end portion,

(d) holder means for said stub,

(e) said holder means including a clamp body member and a tapered seat in said body member in seating engagement with said surface portions,

(f). another member connected to said stub, and

(g) adjustable means engaged between said members for maintaining said stub on said seat with said electrode in vertical alignment.

5. An electrode assembly comprising:

(a) an electrode,

(b) an electrode stub connected to said electrode,

(c) said stub having an end portion adjacent said electrode and surface portions converging toward said end portion,

(d) a clamp body member,

(e) said body member having a stub-receiving recess, an opening through which said stub is insertable into said recess, and another opening through which said end portion of said stub projects,

(f) a tapered seat formed in said recess in engagement with said surface portions,

(g) another member connected to said stub, and

(h) means threadedly engaged in one of said members and bearing against the other of said members so that said stub is held against said seat with said electrode in vertical alignment.

6. The assembly as claimed in claim 5 wherein said another member is a plate secured to said electrode and to said end portion of said stub.

7. The assembly as claimed in claim 5 wherein said another member is detachably connected to said stub and projects into the first-mentioned opening.

8. An electrode assembly comprising:

(a) an electrode,

(b) an electrode stub connected to said electrode,

(c) said stub having one end portion adjacent said electrode, an opposite end portion, and side surfaces converging toward said one end portion,

(d) a clamp body,

(e) said body having an inner cylindrical recess in which said opposite end portion of said stub is disposed, a rst opening into an end of said recess, said stub being insertable into said recess through said first opening, and a second opening through the side wall of said recess, said one end portion of said stub projecting through said second opening, and

(f) a pair of shims mounted in said recess on opp0- site sides of said second opening, said shims forming a tapered seat in engagement with said converging side surfaces of said stub.

9. The assembly as claimed in claim 8 including a plate connected to said end portion of said stub and t0 said electrode, and bolts threaded into said body and bearing against said plate, said bolts being disposed on opposite sides of said second opening so that said stub is maintained against said seat with said electrode in vertical alignment. i

19. The assembly as claimed in claim 8 including a projection on said stub between said converging surfaces, said projection being disposed in said rst opening, and a screw carried by said projection, said screw being disposed in engagement with a wall of said body defining said first opening so that said stub is locked against said seat with said electrode in vertical alignment.

References Cited by the Examiner UNITED STATES PATENTS 881,520 3/1908 Wilson 287-103 1,170,429 2/1916 Dunlap 287`l03 2,413,539 12/1946 Ballard 337-275 X 3,002,466 10/1961 Read 287-103 X 3,215,974 11/1965 Wooding 13-16 X 3,222,494 12/ 1965 OCOnnOr 219--69 FOREIGN PATENTS 86,784 10/1920 Switzerland.

JOSEPH V. TRUHE, Primary Examiner. 

1. AN ELECTRODE CLAMPING DEVICE COMPRISING: (A) AN ELECTRODE STUB, (B) SAID STUB HAVING AN END PORTION ADAPTED TO BE CONNECTED TO AN ELECTRODE AND SURFACE PORTIONS CONVERGING TOWARD SAID END PORTION, AND (C) STUB HOLDER MEANS FOR PERMITTING VERTICAL SELF-ALIGNMENT OF SAID STUB AND A CONNECTED ELECTRODE AND FOR LOCKING SAID STUB IN ALIGNED POSITION, (D) SAID HOLDER MEANS INCLUDING A SEAT HAVING SURFACES ENGAGEABLE WITH SAID STUB SURFACE PORTIONS, SAID STUB SURFACE PORTIONS BEING MOVABLE ON SAID SEAT TO PERMIT VERTICAL SELF-ALIGNMENT OF SAID STUB WHEN THE WEIGHT OF SAID STUB AND A CONNECTED ELECTRODE IS SUPPORTED BY SAID HOLDER MEANS, AND RELEASABLE LOCKING MEANS FOR MAINTAINING SAID STUB AGAINST SAID SEAT WITH THE ELECTRODE IN VERTICALLY ALIGNED POSITION. 